In recent years, a multi-screen synchronized playback technology for continuously playing back high-quality moving image content or the like on multiple large screens is receiving attention. The multi-screen synchronized playback technology is a technology for combining multiple display screens and displaying them as if they are one large screen, or for controlling playback of an image as if one end of a display screen is continuous with one end of another display screen, for example. Furthermore, the multi-screen synchronized playback technology also includes a technology for simultaneously displaying the same image on multiple screens, or for controlling playback so that images simultaneously displayed on multiple screens are integrated to form a whole image.
In relation to the above-described multi-screen synchronized playback technology, the Patent Document 1 mentioned below discloses a technology for splitting a received television signal between a plurality of decoder circuits and displaying the output on multiple screens. However, a technology for providing a terminal for display control for each of a plurality of display devices and performing multi-screen synchronized playback is not disclosed therein. Furthermore, a configuration in which a general-purpose information processing apparatus is used as a terminal for display control is not disclosed therein either. Considering that multi-screen synchronized playback of content with high quality and by a display screen configured from multiple screens will become mainstream, and in light of the present situation where the configuration of a display control terminal is shifting from a dedicated terminal to a general-purpose information processing apparatus, the nature itself of a technical issue required for the multi-screen synchronized playback technology is clearly different from that of the conventional synchronized playback technology.
Incidentally, an information processing apparatus (hereinafter referred to as a “personal computer”; PC) used nowadays in a general-purpose manner is configured to be capable of being connected with a plurality of display devices. For example, by installing a display card (hereinafter referred to as a “DSP card”) in each of a plurality of bus slots formed within, a plurality of display devices can be connected. In this case, it is possible to synchronize high-quality content with high accuracy and playback the content on the screen of the display device connected to each DSP card. However, the number of the display devices that can be connected to one PC is limited to several devices at the most due to a limitation imposed by hardware/software of the PC.
Accordingly, a technology is developed to synchronously playback high-quality content on a large number of display screens without being limited by the display capability of a display control terminal, by installing a plurality of display control terminals (PCs) to which a plurality of display devices are connected and performing time synchronization between the display control terminals with high accuracy. This is a technology in which, when the playback start time set for each content is reached, corresponding display control terminals simultaneously playback the content. However, when a general-purpose PC is used as the display control terminal, since the accuracy of an internal clock of the PC is extremely low, a major problem arises where synchronized playback with high accuracy cannot be realized.
[Patent document 1] JP-A-H11-136594